The present invention relates to an olefin polymerization catalyst and a process for olefin polymerization using the catalyst. More particularly, the invention relates to a novel olefin polymerization catalyst which has a high polymerization activity, and also relates to a process for olefin polymerization using the catalyst.
xe2x80x9ckaminsky catalystsxe2x80x9d are well known as olefin polymerization catalysts. The Kaminsky catalysts exhibit extremely high polymerization activity, and by the use of them, polymers of narrow molecular weight distribution can be obtained. Transition metal compounds known as employable for the Kaminsky catalysts are, for example, bis(cyclopentadienyl)zirconium dichloride (see Japanese Patent Laid-Open Publication No. 19309/1983) and ethylenebis(4,5,6,7-tetrahydroindenyl)zirconium dichloride (see Japanese Patent Laid-Open Publication No. 130314/1986). It is also known that the olefin polymerization activity and the properties of the resulting polyolefins greatly vary when different transition metal compounds are used in the polymerization. Recently, transition metal compounds having a ligand of diimine structure have been proposed as novel olefin polymerization catalysts (see International Patent Publication No. 9623010).
By the way, polyolefins generally have excellent mechanical properties, so that they are used in many fields such as fields of various molded products. However, with the diversification of requirements for the properties of polyolefins, polyolefins of various properties have been desired in recent years. Moreover, increase of productivity has been also desired.
Under such circumstances as mentioned above, there has been desired development of olefin polymerization catalysts exhibiting excellent olefin polymerization activity and capable of producing polyolefins of excellent properties.
It is an object of the invention to provide an olefin polymerization catalyst exhibiting an excellent olefin polymerization activity and a process for olefin polymerization using the catalyst.
The olefin polymerization catalyst according to the present invention comprises:
(A) a transition metal compound represented by the following formula (I): 
xe2x80x83wherein M is a transition metal atom selected from Group 3 to Group 11 of the periodic table,
U1 is a carbon atom having a substituent group R2, a nitrogen atom or a phosphorus atom,
A is a nitrogen atom or a phosphorus atom,
Q is a carbon atom having a substituent group R3, a nitrogen atom or a phosphorus atom,
S1 is a carbon atom having a substituent group R4, a nitrogen atom or a phosphorus atom,
T is a carbon atom having a substituent group R5, a nitrogen atom or a phosphorus atom,
m is an integer of 2 to 6,
R1 to R5 may be the same or different, when M is a transition metal atom selected from Group 3 to Group 5 and Group 7 to Group 11 of the periodic table, they are each a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group, and when M is a transition metal atom selected from Group 6 of the periodic table, R1 is a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group and R2 to R5 are each a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group,
two or more of R1 to R5 may be bonded to each other to form a ring, and one group of R1 to R5 contained in one ligand and one group of R1 to R5 contained in another ligand may form a bridging group or a single bond,
n is a number satisfying the valence of M, and
X is a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, a boron-containing group, an aluminum-containing group, a phosphorus-containing group, a halogen-containing group, a heterocyclic compound residual group, a silicon-containing group, a germanium-containing group or a tin-containing group, and when n is 2 or greater, plural groups indicated by X may be the same or different to each other and plural groups indicated by X may be bonded to each other to form a ring.
The olefin polymerization catalyst according to the present invention comprises:
(A) Transition metal compound represented by the above formula (I), and
(B) at least one compound selected from:
(B-1) an organometallic compound,
(B-2) an organoaluminum oxy-compound, and
(B-3) a compound which reacts with the transition metal compound (A) to form an ion pair.
The olefin polymerization catalyst according to the present invention may further comprise a carrier (C) in addition to the transition metal compound (A) and at least one compound (B) selected from the organometallic compound (B-1), the organoaluminum oxy-compound (B-2) and the compound (B-3) which reacts with the transition metal compound (A) to form an ion pair.
The process for olefin polymerization according to the present invention comprises polymerizing or copolymerizing an olefin in the presence of the above-mentioned olefin polymerization catalyst.